Todd Moody wrote:

> The GJ Nelson work recently posted by Gary Jackson supports what
> Andrew has been saying, namely that dietary AA, even in
> substantial amounts (1.5g/day above the normal 200mg, or about 23
> egg yolks' worth) has no measurable impact on health, at least
> not during a 50-day trial).  In fact, it seems that in the
> presence of a liberal amount of AA and a small amount of EPA, the
> D5D enyzme is switched off and the body produces no additional AA
> at all.

This is probably due to a negative feedback loop.  As product
concetration increases the enzyme controlling production undergoes a
conformational (shape) change which "covers up" the active sites
responsible for converting the precursors to product.

> This suggests (to me) that the endogenous AA system is an
> emergency backup system, to get us through times when meat is
> scarce.  My speculation is that the health problems are the
> result of the backup system being chronically and inappropriately
> activated by insulin, which indeed upregulates D5D.

Bingo!  Bingo!  Bingo!

> I was intrigued by the comment in one of the Nelson studies to
> the effect that AA took the place of LA in the cells.  If I am
> not mistaken, LA is far more oxidation-prone than AA, so the
> presence of AA would tend to reduce the probability of oxidation
> of LDL, etc.

If this is true it could account for a possible anti-arthrogenic effect
of a Neanderthin diet.  Ant thoughts?

Andrew  =8-)
--
Andrew S. Bonci, BA, DC, DAAPM
Assistant Professor, Department of Diagnosis
Cleveland Chiropractic College
6401 Rockhill Road
Kansas City, Missouri   64131
(816) 333-7436 ex39